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Code Issues Releases Wiki Activity

Native outgoing data

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This commit is contained in:
M66B 2016-01-14 19:30:38 +01:00
parent 2636a4dddb
commit 85dc20b272
1 changed files with 29 additions and 10 deletions
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39
app/src/main/jni/netguard/netguard.c
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@ -67,6 +67,8 @@ int canWrite(const int);
int writeSYN(const struct connection *, const int);
int writeACK(const struct connection *, struct data *, uint16_t confirm, int);
void decode(JNIEnv *, jobject, const struct arguments *args, const uint8_t *, const uint16_t);
jint getUid(const int, const int, const void *, const uint16_t);
@ -305,12 +307,14 @@ void *handle_events(void *a) {
__android_log_print(ANDROID_LOG_ERROR, TAG, "getsockopt error %d: %s",
errno, strerror(errno));
cur->state = TCP_CLOSE;
cur = cur->next;
continue;
}
if (serr) {
__android_log_print(ANDROID_LOG_ERROR, TAG, "SO_ERROR %d: %s",
serr, strerror(serr));
cur->state = TCP_CLOSE;
cur = cur->next;
continue;
}
}
@ -349,6 +353,16 @@ void *handle_events(void *a) {
__android_log_print(ANDROID_LOG_DEBUG, TAG,
"recv socket lport %u bytes %d",
cur->lport, bytes);
struct data *data = malloc(sizeof(struct data));
data->len = bytes;
data->data = malloc(bytes);
memcpy(data->data, buffer, bytes);
// canWrite(args->tun)
writeACK(cur, data, 0, args->tun);
// TODO retransmits
free(data->data);
free(data);
cur->local_seq += bytes;
}
}
}
@ -493,7 +507,7 @@ void handle_tcp(JNIEnv *env, jobject instance, const struct arguments *args,
__android_log_print(ANDROID_LOG_WARN, TAG, "Processed ack");
else {
__android_log_print(ANDROID_LOG_DEBUG, TAG, "New ack");
if (data != NULL && data->len) {
if (data != NULL) {
// TODO non blocking
__android_log_print(ANDROID_LOG_DEBUG, TAG, "send socket data %u",
data->len);
@ -501,7 +515,7 @@ void handle_tcp(JNIEnv *env, jobject instance, const struct arguments *args,
__android_log_print(ANDROID_LOG_ERROR, TAG, "send error %d: %s",
errno, strerror(errno));
else {
if (writeACK(cur, data->len, args->tun))
if (writeACK(cur, NULL, data->len, args->tun))
cur->remote_seq += data->len;
}
}
@ -659,12 +673,15 @@ int writeSYN(const struct connection *cur, int tun) {
return res;
}
int writeACK(const struct connection *cur, uint32_t datalen, int tun) {
int writeACK(const struct connection *cur, struct data *data, uint16_t confirm, int tun) {
// Build packet
uint16_t len = sizeof(struct iphdr) + sizeof(struct tcphdr); // no data
uint16_t datalen = (data == NULL ? 0 : data->len);
uint16_t len = sizeof(struct iphdr) + sizeof(struct tcphdr) + datalen; // no data
u_int8_t *buffer = calloc(len, 1);
struct iphdr *ip = buffer;
struct tcphdr *tcp = buffer + sizeof(struct iphdr);
if (datalen)
memcpy(buffer + sizeof(struct iphdr) + sizeof(struct tcphdr), data->data, data->len);
// Build IP header
ip->version = 4;
@ -682,13 +699,13 @@ int writeACK(const struct connection *cur, uint32_t datalen, int tun) {
tcp->source = cur->dest;
tcp->dest = cur->source;
tcp->seq = htonl(cur->local_seq);
tcp->ack_seq = htonl(cur->remote_seq + datalen); // TODO proper wrap around
tcp->ack_seq = htonl(cur->remote_seq + confirm); // TODO proper wrap around
tcp->doff = sizeof(struct tcphdr) >> 2;
tcp->ack = 1;
tcp->window = htons(2048);
// Calculate TCP checksum
uint16_t clen = sizeof(struct ippseudo) + sizeof(struct tcphdr);
uint16_t clen = sizeof(struct ippseudo) + sizeof(struct tcphdr) + datalen;
uint8_t csum[clen];
// Build pseudo header
@ -697,10 +714,12 @@ int writeACK(const struct connection *cur, uint32_t datalen, int tun) {
pseudo->ippseudo_dst.s_addr = ip->daddr;
pseudo->ippseudo_pad = 0;
pseudo->ippseudo_p = ip->protocol;
pseudo->ippseudo_len = htons(sizeof(struct tcphdr)); // no data
pseudo->ippseudo_len = htons(sizeof(struct tcphdr) + datalen); // no data
// Copy TCP header
// Copy TCP header + data
memcpy(csum + sizeof(struct ippseudo), tcp, sizeof(struct tcphdr));
if (datalen)
memcpy(csum + sizeof(struct ippseudo) + sizeof(struct tcphdr), data->data, data->len);
tcp->check = checksum(csum, clen);
@ -709,9 +728,9 @@ int writeACK(const struct connection *cur, uint32_t datalen, int tun) {
// Send packet
__android_log_print(ANDROID_LOG_DEBUG, TAG,
"Sending ACK to tun %s/%u seq %u ack %u",
"Sending ACK to tun %s/%u seq %u ack %u data %u confirm %u",
to, ntohs(tcp->dest),
ntohl(tcp->seq), ntohl(tcp->ack_seq));
ntohl(tcp->seq), ntohl(tcp->ack_seq), datalen, confirm);
int res = write(tun, buffer, len);
if (res < 0) {
// TODO handle EINTR